Friday, May 18, 2018

Tree of the Week: Shortleaf Pine (Pinus echinata)

By and large, the weather was very pleasant March through April, with regular rains and 70-degree days. We had nice spring weather. Now that it's the middle of May, things have changed: over the past couple of weeks we have had negligible amounts of rain and 90-degree days. Tomorrow is expected to be another hot one.

During these hot and dry days it's good to think about those hardy native trees that are best adapted to survive the sometimes-grueling Louisiana summers. The shortleaf pine (Pinus echinata) is one such specimen. This tree is suited to a wide variety of soil types and it can withstand a little drought, and seems to prefer drier conditions. There are two individual shortleaf pines in the arboretum, for your inspection.
The two shortleaf pines are pictured on either side of the sidewalk. The tall, slender trunks should be discernible but the evergreen foliage blends into the background. In October 1997, the trees were acquired from Coyote Creek Nursery, located in southeastern Louisiana. The little trees were planted the following month. The photo above illustrates their tolerance for different growing conditions. The two trees are approximately the same size, even though one is growing in an irrigated grassy area while the other is growing outside of the irrigation zone and without ground covering.
The tree outside of the irrigation zone seems to be faring a little better. The trunk is certainly straighter. It's pictured above. The Student Union Building is pictured in the background. This is the western edge of the arboretum, on a slope.
The short leaves measure under four inches. They are short compared to the loblolly pine needles.
The needles grow in pairs. Needle length varies. Some leaves are approximately 3.5 inches.
Other leaves are closer to 2.5 inches.
The egg-shaped pine cones are hanging from the branches. Cones can be found on the ground, too.
This cone was removed from a low-hanging branch. It's approximately 2 inches in length.
This particularly conical cone was found on the ground and measures approximately 3 inches.
New, green cones are developing while the old ones remain on the branches.
The bark is reddish-brown and rough. The plates are smoother, flatter, and thinner compared to loblolly pine bark.



You can find more pictures of the arboretum's shortleaf pines here.

For more information about this species consult the following:
United States Department of Agriculture
U.S. Forest Service
Virginia Tech Dendrology
NC State Extension 

Springtime Flowers

The arrow wood viburnum (Viburnum dentatum) is covered in blossoms this week.
This bush is growing in full sun on a slope. Other arrow wood viburnums have volunteered in very shady locations: they are growing taller in the shade, but they do not have as many blossoms.

Wednesday, May 16, 2018

Immature Fruit

The black hickory (Carya texana) isn't wasting any time this spring. Less than a month ago we were measuring catkins, and now we already see substantially developed fruits.
The large fruits are still growing.


Immature Fruit


The pond cypress (Taxodium ascendens) near the Fitness Center is ornamented with clusters of developing fruits.
The globular fruits are bright green.

Immature Fruit

In the middle of May, we are seeing immature fruits on the fringe trees (Chionanthus virginicus).
Occasionally, volunteer fringe trees will spring up in the arboretum, and sometimes those volunteers are added to the collection.

Springtime Flowers

This is a sweet-shrub (Calycanthus floridus) bush. It also goes by the name Carolina allspice. The bush is flowering right now, but the flowers aren't readily noticed.
The dark red flowers are fragrant!


Springtime Flowers


Smooth sumac (Rhus glabra) flowers are tiny and not showy, but the large pancile is conspicuous.
Little green-white flowers are densely clustered together.